102 LIMNJEID^E. 



A. Shell extremely thin and fragile, and almost enveloped by 

 an outer lobe or membranous expansion of the mantle : 

 spire very short. 



1. LIMN^A GLUTINO'SA*, Mliller. 



Buccinum glutinosum, Mull. Verm. Hist. pt. ii. p. 129. Limn&m 

 glutinosus, F. & H. iv. p. 182, pi. cxxiv. f. 6, 7. 



BODY dark grey, with a greenish-yellow tinge and bright- 

 yellow or whitish specks : tentacles very short, rather triangular, 

 with blunt tips : eyes placed on tubercles on the inner side of 

 the tentacles, very black and distinct -.foot exceedingly large, 

 broad in front and obtusely rounded before and behind. 



SHELL globosely-oval, so excessively thin as to be al- 

 most membranous, highly polished, transparent, yellowish or 

 greyish-horncolour, with a few indistinct darker spiral zones, 

 remotely and irregularly striate by the lines of growth, 

 which are stronger towards the suture, and closely but 

 microscopically striate in a spiral direction : epidermis ex- 

 tremely thin : whorls 3-4, globular, the last forming nearly 

 the whole of the shell : spire slightly produced : suture 

 rather deep : mouth oval, a little contracted above by the 

 projection of the penultimate whorl : outer lip very thin : 

 inner lip much spread on the columella and thickened at its 

 edges : columellar/bZc? (forming the lower part of the pillar 

 of the spire) curved and sharp. L. 0'55. B. 0*45. 



Var. mucronata. Shell not quite so globular : spire more 

 produced. 



HABITAT : Lakes and ponds in the home and eastern 

 counties, as well as in a ditch near Dunster Castle in 

 Somersetshire (Leach) ; Bala Lake (Gibbs) and a pond 

 near Windermere (Bulwer) ; but it is a local species, 

 although abundant where it occurs. Its periodical re- 

 appearance in the same spots has been remarked both 

 by Mr. Bridgman and Mr. Whiteaves to be very uncer- 

 tain and unaccountable. Specimens have been kindly 

 sent to me by Mr. Bridgman, in which the spire is more 



* Slimy. 



